Circuit of The Americas today announced that it has been declared ready to host the 2012 F1 United States GP by Charlie Whiting, who directs racing, safety and technical matters for the FIA. Whiting visited the Central Texas racing circuit as part of a scheduled pre-race inspection and approved the circuit for “Grade 1” status, hence appropriate to host an F1 race.

I think that may have been Korea. Frankly I think for the reporters to get any benefit from windows, other than just making it a nicer space, would be if they overlooked the pits - and it doesn't look like the building is in a position to allow that. Do they also make available press boxes over the main grandstand, or is that usually all private boxes?

Those aerial pics show a lot of civil works, ie the culverts and retaining walls. There's been a lot of hidden work on that site.

I'm also continually baffled by US use of downstand beams, a form of construction that was pretty much superseded in the UK (and most of EU) by flat slab construction about 20 years ago. Flat slab gives a 1 week turnaround, while deep beams will add a couple of days to that cycle. Also, you can see the wasted space between the beams and the HVAC ducts running under the beams. Now if you delete the beams, the HVAC can run under the slab, that gives a much simpler building for integrating services.

They are suitable in stiff clays...The main advantage of the down-stand beam raft foundation is that it provides a level surface slab which can form the ground floor of the building. Another advantage is the saving in excavation costs.

Plain flat slab rafts are suitable for lightly loaded structures such as small houses. They are also be used for heavier structures if the ground condition is good and no differential settlement is expected.

So...Couldn't it come down to the soil and the size??

Motorsport without danger is like cooking without saltSir Stirling Moss

He's taking about the floor framing. Richard, my guess is that with Houston being close to the Gulf that there are some increased wind load requirements and they didn't want shear walls. Not sure what the seizmic requirements are there either. I will say that I typically only see flat slab used here in condos, low rise hotels, parking garages, etc. where floor to floor hts. are king. I don't have a lot of experience in commercial work though, so someone else might be able to provide a better answer for you. Personally, it seems I see more composite steel frame and slab these days than anything else.

I will also say that my structures professor had a bias for beams and that might be pervasive.

They might also be doing a bit of fast tracking and wanted some flexibility.

edit - actually Richard, if you check the aerial, they've got a massive span and cantilever thing going on in the main part of the garages, aaaand in the interior shot it looks like they've got some column offsets they're dealing with.